1. Field of the Invention
The present invention relates to route guidance used when a satellite positioning function of a navigation system becomes disabled.
2. Description of the Related Art
Japanese Patent Application Publication No. 2007-101379 discloses a technology of route guidance when a satellite positioning function provided by a navigation apparatus becomes disabled. This publication discloses that when a satellite positioning function becomes disabled and a road section is previously defined, and when a guide point for guiding a route change is present within a road section, the guide point is brought forward a position before driving to the road section to guide the guide point.
Japanese Patent Application Publication No. 2007-101379 discloses that when a satellite positioning function becomes disabled, for proper guidance to be provided, a road section must be previously defined. Further, when the satellite positioning function becomes disabled at the outside of the road section, suitable route guidance cannot be provided.